A similar memory map to the above, showing offset values for each position
on the screen. Handy for when you're writing video routines.
This was written by Alessandro
Scotti, who has a really cool
Pac Emulator

T o o l s

I use ZCC myself, which is a Small C variant. Source code available from
that site, or you can just
download my tweaked
version, which compiles cleanly, and has a few helpful targets, placing
binaries in a 'bin' directory. Or you can download the unmodified
zcc096.zip.
(source)

MAME is a tool? Yup. It emulates the target hardware that we are
building for! So it's worth more than just to play games. ;) There
are links to downloads for all sorts of systems. I personally took
the unix source, and compiled it with the debugger active. (Read
MAME's docs for how to do this.) So that I can look at the registers and
RAM and such to see if my programs are doing what they're supposed to.

R o m s e t s

All screengrabs were generated with the emulator MAMEUnless otherwise noted, all source code is FREEWARE.

This is my first major entrance into sound programming for Pac
hardware. It will step through 16 steps on the screen, displaying
the current one on the top of the screen. The columns are:
Green: Waveform select (0..7)
Red: Frequency select (0000..ffff)
Blue: Volume (0..f)
Joystick moves the white cursor.
P1 and P2 start change the value.
P1 and P2 coins change the speed.
moving with 'service' on copies the value around.
The current copy character next to the 'C'.
The speed is next to the 'S'

THESE ROMS WILL PROBABLY NOT WORK ON REAL HARDWARE! You may have to flip the 'service' switch for this to start.

The first test rom I made from scratch. This is my "Hello, World!" rom,
to prove to myself that I had a basic understanding of the tools and
the hardware. I've been constantly updating it, and using it as a
test platform to understand the hardware and techniques. Watch the
red ghost's eyes as you drive him around with the joystick.

THESE ROMS SHOULD WORK ON REAL HARDWARE! You may have to flip the 'service' switch for this to start.

All that has to be done is a simple toggle in the Config.mk makefile
to build this same program for either Pac-Man or Pengo hardware. It
simulates the green text waterfall, as seen in the movie "The Matrix".

THESE ROMS SHOULD WORK ON REAL HARDWARE! You may have to flip the 'service' switch for this to work.

NOTE: These romsets might contain some modified graphics from an original
Pac-Man or Pengo romset. This graphics rom modification is not endorsed by
NAMCO or SEGA in any way. The likenesses of the ghosts and pac man are
trademarked by NAMCO. The likenesses of Pengo and the Sno-Bees are
trademaeked by SEGA.

A c k n o w l e d g m e n t

First of all, I need to say that the arcade collecting community on
RGVAC have
been very helpful and friendly... even those people with products
that might be competition with projects I'm working on. You
guys/gals really rock. Thanks alot for being so extremely cool
about everything.
I guess we all have a common goal... to keep this old hardware
preserved, working, and in circulation, providing pleasure to
whomever uses it. :D

Clay has supplied me with a lot of practical information about
writing programs that can actually be run on real hardware. It
was from some sample source that he sent me that I was able to
better understand the Watchdog Timer, as well as the VBLANK IRQ
information. Thanks muchly, Clay!

Dave helped me out a lot with getting an understanding about the
sound hardware, and let me peek at some of his sound generation
code. He's got kickass games that run on pac hardware
on his site. very cool.

I've been involved with CSH since I was a frosh in college, and I've
kept in contact with everyone there... some years more than others,
but everyone there has always been open for "the old folk" to get
back involved with stuff. When I asked to borrow one of the EPROM
programmers, no one told me no. (Granted, no one really told me yes
either... but still.) I'm still trying to get the damned thing working,
but the fact that I could borrow it at all is way cool.
I soon will have a seminar at CSH about doing all of the stuff listed
in the docs and such above.

Many of my friends have been very supportive of this effort, and
just their simple "that's pretty cool" or "you are such a geek"
comments have helped motivate me to push onwards with this effort.
Granted this link doesn't go to most of them, but it's a start. ;)
Thanks!

If you're looking to hack Pac-Man the game, you might be better off
at starting over
here, although there's a lot of good information here as well.